Rigol HDO1000 and HDO4000 12bit oscilloscopes launched in China

[core]

A short test for the low pass digital filter.

An Axiomet AX-3004H power supply. 5V, switching frequency about 106kHz
Rigol DL3000 load, CC cycle mode, 50Hz, 150mA <-> 1,5A

Math 2 : Low-pass filter, scale 25mV/div.
10ms -> minimum lowpass frequency 25kHz
5ms -> minimum lowpass frequency 50kHz
2ms -> minimum lowpass frequency 250kHz

Triggering on ch1 no problem, HFR coupling.
Measurements on Math 2 are clear and reliable.
FFT is OK, but could be better than that.

The measurement environment is not optimised and the cables pick up some of the noise.
The idea was to check if the the LowPass filter is useful for a such application.

Later edit : the minimum lowpass filter frequency above is for an acquisition memory of 1MB.

[Fungus]

What if you do FFT of Math2?

[core]

FFT source must be a channel : CH1 - CH4.
Can't do math on math.

[ebastler]

FFT source must be a channel : CH1 - CH4.
Can't do math on math.

Some Math functions do work on Math results, but not FFT.

[Fungus]

FFT source must be a channel : CH1 - CH4.
Can't do math on math.

I just checked because I did it earlier today...

You can use math as source for most functions but not FFT.

Maybe it's because FFT is done in the FPGA or something. 

[Martin72]

You can use math as source for most functions but not FFT.

Also does not work with the siglent scopes.

Edit:Misunderstood

[core]

A short test for the low pass digital filter.

An Axiomet AX-3004H power supply. 5V, switching frequency about 106kHz
Rigol DL3000 load, CC cycle mode, 50Hz, 150mA <-> 1,5A

Math 2 : Low-pass filter, scale 25mV/div.
10ms -> minimum lowpass frequency 25kHz
5ms -> minimum lowpass frequency 50kHz
2ms -> minimum lowpass frequency 250kHz

Triggering on ch1 no problem, HFR coupling.
Measurements on Math 2 are clear and reliable.
FFT is OK, but could be better than that.

The measurement environment is not optimised and the cables pick up some of the noise.
The idea was to check if the the LowPass filter is useful for a such application.

Later edit : the minimum lowpass filter frequency above is for an acquisition memory of 1MB.

Another capture, using 3 Math functions. 2 x LPF filter for normal and zoom waveforms, and FFT.

[core]

Same signal for MSO5000. Same filter.
Measurements are OK.
Can't do the LPF filter when zoom is activated (filters are disabled in meniu).

And just to be all together, SDS1104X-E (filters not available) and Uni-T UPO1202CS (it seems that filter is using the display data only).

[Performa01]

You can use math as source for most functions but not FFT.

Also does not work with the siglent scopes.

You should rethink that statement.

FFT results cannot be the source for math operations, but Math (incl. FFT) can take channel traces, zoom traces, memory traces and math traces as operands.

[ebastler]

Another capture, using 3 Math functions. 2 x LPF filter for normal and zoom waveforms, and FFT.

The dedicated counter is limited to working on the physical inputs -- but measurements (both cursor-based and automatic) can be applied to Math results without restrictions, right?

Just out of curiosity: Can you apply automated measurements, as well as further Math operations, to the FFT spectrum? Not sure whether there is anything useful to be measured or calculated, but still...

[2N3055]

You can use math as source for most functions but not FFT.

Also does not work with the siglent scopes.

I don't know, i think it does.....

In attachment:
- noisy 1MHz into CH1.
- Math2 (F2) Average(C1)
- Math1 (F1) FFT on (F2)
- Math3 (F3) FFT on (C1)

First image are signals. Second image are  FFT-s. Different timebase for nicer FFT res.

You can also do this:  FFT(Filter(C1*C2)) in single math channel. And do that 4 times...

And also you can have Memory channel as a source. Which is interesting because that means you have original data saved instead of result. So you can later on change FFT parameters when comparing to something.

Siglent's math is on completely another level.. R&S don't have it on MXOx.. They are working on it though...

[ebastler]

- noisy 1MHz into CH1.
- Math2 (F2) Average(C1)
- Math1 (F1) FFT on (F2)
- Math3 (F3) FFT on (C1)

That's pretty impressive. Done on the SDS2000X HD, I assume? Which is unfortunately outside of my price range, and not a direct competitor of Rigol's DHO1000 series.

Ah, if only Siglent could make up their mind about the SDS1000X HD... With the increasing rumours about the Q1 release of the 800X HD outside of China, it seems uncertain again whether the 1000X HD will come here at all?

[2N3055]

- noisy 1MHz into CH1.
- Math2 (F2) Average(C1)
- Math1 (F1) FFT on (F2)
- Math3 (F3) FFT on (C1)

That's pretty impressive. Done on the SDS2000X HD, I assume? Which is unfortunately outside of my price range, and not a direct competitor of Rigol's DHO1000 series.

Ah, if only Siglent could make up their mind about the SDS1000X HD... With the increasing rumours about the Q1 release of the 800X HD outside of China, it seems uncertain again whether the 1000X HD will come here at all?

Yes that is 2000XHD, that is what I have.
But from what I hear that little one will be able to mostly do the same.
As for 1000XHD I'm sorry but I honestly don't know. I don't care much about rumors and I have no knowledge of official info on that topic.
I hope it does, it is an excellent scope in its class.

[Martin72]

I don't know, i think it does.....

I tried it last night and got the message "not supported".
I'll try it again tonight

[Martin72]

You can use math as source for most functions but not FFT.

Also does not work with the siglent scopes.

You should rethink that statement.

FFT results cannot be the source for math operations, but Math (incl. FFT) can take channel traces, zoom traces, memory traces and math traces as operands.

But that was exactly the point, whether FFT can be used as a source and after I tested it again to be sure, I said no.
And I didn't mean anything other than that.

[voltsandjolts]

Well, I didn't really need another scope, but at £620 DH1074 looked like a bit of fun, so I took the plunge on my first ever bit of Rigol test kit, with low to medium expectations of customer satisfaction :-)

First impressions:
Fan is a little bit noisy, in a low-pitch 'whooshing' sort of way. Not too bad.
Display is excellent, for UI elements and traces, very crisp and clear. Nice fonts.
The UI layout and operation with touch and buttons is very good. Quite intuitive.
Touch and feel of buttons and knobs is good. Plastics quality is good.

The DC accuracy of all 4 channels is within the 2% specification. However, at low frequencies CH1 reads about 4% lower than other channels. For example, with all probes x1 connected to scope comp output, hit Default then AUTO. All 4 traces overlay perfectly. Switch to x10, hit AUTO. CH1 very obviously different, showing 4% lower amplitude than other channel traces (with probes on x10 the input channel relays have switched to the lower input range).

Do your traces overlay perfectly in that setup?

[core]

Another capture, using 3 Math functions. 2 x LPF filter for normal and zoom waveforms, and FFT.

The dedicated counter is limited to working on the physical inputs -- but measurements (both cursor-based and automatic) can be applied to Math results without restrictions, right?

Just out of curiosity: Can you apply automated measurements, as well as further Math operations, to the FFT spectrum? Not sure whether there is anything useful to be measured or calculated, but still...

I've checked. Please see below.

Ch1 : rectangular waveform, 1MHz, 600mVpp

Math 1 : High Pass filter 10MHz
Math 2 : Math 1 + Ch1
Math 3 : FFT(Ch1)
Math 4 : Math1 - Math2

Masurements are made for Math 4 : Vpp, AC rms, Freq

In the pictures you can check that the counter source must be a hw input : Ch1 - Ch4 and Ext

Later edit : measurements are available even for Math 3, but they are meaningless for FFT - most of them.

[Performa01]

You can use math as source for most functions but not FFT.

Also does not work with the siglent scopes.

You should rethink that statement.

FFT results cannot be the source for math operations, but Math (incl. FFT) can take channel traces, zoom traces, memory traces and math traces as operands.

But that was exactly the point, whether FFT can be used as a source and after I tested it again to be sure, I said no.
And I didn't mean anything other than that.

Sorry, but I have difficulties understanding you. When someone says "You can use math as source for most functions but not FFT" then that means you can not use math as source for FFT, not vice versa, right?

[ebastler]

For example, with all probes x1 connected to scope comp output, hit Default then AUTO. All 4 traces overlay perfectly. Switch to x10, hit AUTO. CH1 very obviously different, showing 4% lower amplitude than other channel traces (with probes on x10 the input channel relays have switched to the lower input range).

Have you tried swapping probes, to check whether the difference lies in the probes or in the scope frontend?
If it is indeed the latter, have you run a self-calibration (after warming up the scope)?

[voltsandjolts]

Yes, warm-up and self cal done (several times).
Also swapped probes amoung channels, no change, so CH1 frontend is causing this.

[core]

You can use math as source for most functions but not FFT.

Also does not work with the siglent scopes.

I don't know, i think it does.....

In attachment:
- noisy 1MHz into CH1.
- Math2 (F2) Average(C1)
- Math1 (F1) FFT on (F2)
- Math3 (F3) FFT on (C1)

First image are signals. Second image are  FFT-s. Different timebase for nicer FFT res.

You can also do this:  FFT(Filter(C1*C2)) in single math channel. And do that 4 times...

And also you can have Memory channel as a source. Which is interesting because that means you have original data saved instead of result. So you can later on change FFT parameters when comparing to something.

Siglent's math is on completely another level.. R&S don't have it on MXOx.. They are working on it though...

If we consider that the DHO4000 it's in the same price range as Siglent SDS2000 HD, the answer is simple.

That's why I've bought DHO1000 for the BF price. More than that is too expensive.

DHO1000 can do FFT only for CH1 - Ch4. See below the screen capture. So Yeah 

[ebastler]

Yes, warm-up and self cal done (several times).
Also swapped probes amoung channels, no change, so CH1 frontend is causing this.

Hmm... DC Gain is specified as 2% at full scale, so if the auto-setting did set the gain to use the full scale (more or less), one can argue that the scope is out of spec slightly. Personally I wouldn't be concerned, but will have a look at my DHO1074 when I get to play with it. For the moment, I have all but forgotten about it until Christmas eve. 

I found a "Performance Verification Manual", by the way -- only by chance, and only on the ManualsLib site; could not spot it on any Rigol site. Mildly interesting, I'd say: https://www.manualslib.com/manual/3029727/Rigol-Dho1000-Series.html#manual

Edit: Rigol's North America site has it too, on the product page, after scrolling down a bit and selecting the "Manuals" tab:
https://www.rigolna.com/products/digital-oscilloscopes/dho1000/

[Martin72]

@performa01:

Ah....ahhhh...
Then I had misunderstood, sorry.
The other one works of course, I could have said that without testing.

[2N3055]

You can use math as source for most functions but not FFT.

Also does not work with the siglent scopes.

I don't know, i think it does.....

In attachment:
- noisy 1MHz into CH1.
- Math2 (F2) Average(C1)
- Math1 (F1) FFT on (F2)
- Math3 (F3) FFT on (C1)

First image are signals. Second image are  FFT-s. Different timebase for nicer FFT res.

You can also do this:  FFT(Filter(C1*C2)) in single math channel. And do that 4 times...

And also you can have Memory channel as a source. Which is interesting because that means you have original data saved instead of result. So you can later on change FFT parameters when comparing to something.

Siglent's math is on completely another level.. R&S don't have it on MXOx.. They are working on it though...

If we consider that the DHO4000 it's in the same price range as Siglent SDS2000 HD, the answer is simple.

That's why I've bought DHO1000 for the BF price. More than that is too expensive.

DHO1000 can do FFT only for CH1 - Ch4. See below the screen capture. So Yeah 

DHO1000 is different price range for sure. Especially if you got it at 40% discount.
Many people don't need/use advanced math.

Funny thing is that  it is not Siglent that is in problem here. Their scopes have added value and price is great for higher quality.
But you know who is more in problem?

DHO1000 basically has almost same features as R&S RTB2000 in analysis (RTB2000 is very basic scope, except excellent BODE).
DHO1000 has more memory, more resolution, etc.. DHO1000 mathi is pretty much copy how R&S did it on RTB2000. Many GUI concepts too.
In many parameters directly competes with RTB2000.

If only Rigol would take seriously software quality, RTB2000 would be in real trouble..
At this moment, RTB is, of course, serious and mature product and Rigol has long way to go to finish the platform...

[voltsandjolts]

Yes, warm-up and self cal done (several times).
Also swapped probes amoung channels, no change, so CH1 frontend is causing this.

Hmm... DC Gain is specified as 2% at full scale, so if the auto-setting did set the gain to use the full scale (more or less), one can argue that the scope is out of spec slightly. Personally I wouldn't be concerned, but will have a look at my DHO1074 when I get to play with it. For the moment, I have all but forgotten about it until Christmas eve. 

I found a "Performance Verification Manual", by the way -- only by chance, and only on the ManualsLib site; could not spot it on any Rigol site. Mildly interesting, I'd say: https://www.manualslib.com/manual/3029727/Rigol-Dho1000-Series.html#manual

Edit: Rigol's North America site has it too, on the product page, after scrolling down a bit and selecting the "Manuals" tab:
https://www.rigolna.com/products/digital-oscilloscopes/dho1000/

I don't think the scope is out of spec, it meets the DC Gain specification for sure. I haven't seen any vertical gain AC specifications, other than bandwidth. This is just my OCD and curious what other owners see 

Thanks for links, will take a look.